Device for forming a tube provided with gussets

Abstract

A device for forming a tube provided with gussets out of a single- or multi-layer, continuously pre-stressed material web consists of divided upper and lower folding plates mounted on the machine frame that determine the width of the tube to be formed when it is laid flat, which approach one another with regard to their distance from one another approximately in the shape of a wedge and in a manner perpendicular to the plane of the tube to be formed, beginning from the approach sides, with the wedge angle being adjustable, and with the device having two rows of insertion discs respectively mounted on carriers reaching between the folding plates for forming the gussets, whose distance from one another may be adjusted in the plane of the tube to be formed. In order to decrease the number of adjustment procedures when changing the format, an adjustment device of both rows of insertion discs on the middle level between the upper and lower folding plates is directly or indirectly connected to a device for displacing both rows of insertion discs in such a manner that the angle formed by the common tangents of both rows of insertion discs is sufficiently large that the insertion discs essentially firmly supply the interior folding edges of the gussets.

What is claimed is:  
     
       1. A device for forming a tube provided with gussets out of a single-layer or multi-layer, continuously pre-stressed material web comprising: 
       divided upper and lower folding plates mounted in a machine frame that determine a width of the tube when it is laid flat and over whose entrance sides the web is deflected in order to raise overlapping edge regions to be pressed in, said plates being adjustable in their distance from one another corresponding to the width of the tube to be formed and approaching one another in a direction of an exit region, at a right angle to a tube-forming plane and approximately in the shape of a wedge with an adjustable wedge angle;  
       two rows of insertion disks, each mounted on carriers and engaging in a middle level between the upper and lower folding plates for forming gussets, a distance between said rows being adjustable in the tube-forming plane; and  
       an adjusting device for both rows of insertion disks on the middle level between the upper and lower folding plates and connected to a device for displacing both rows of insertion disks in such a way that an angle formed by common tangents of both rows of insertion disks is sufficiently large that the insertion disks essentially firmly supply interior folding edges of the gussets, said carriers in said exit region being secured on capping pieces mounted to said frame such that said capping pieces can pivot around a crosswise axis while said carriers can pivot around a vertical axis, said carriers in an entrance region being pivotally mounted on said capping pieces and movable relative thereto in the plane of the insertion disks by a lever mechanism.  
     
     
       2. A device for forming a tube provided with gussets out of a single-layer or multi-layer, continuously pre-stressed material web comprising: 
       divided upper and lower folding plates mounted in a machine frame that determine a width of the tube when it is laid flat and over whose entrance sides the web is deflected in order to raise overlapping edge regions to be pressed in, said plates being adjustable in their distance from one another corresponding to the width of the tube to be formed and approaching one another in a direction of an exit side, at a right angle to a tube-forming plane and approximately in the shape of a wedge with an adjustable wedge angle;  
       two rows of insertion disks, each mounted on carriers secured in a capping piece and engaging in a middle level between the upper and lower folding plates for forming gussets, a distance between said rows being adjustable in the tube-forming plane; and  
       an adjusting device for both rows of insertion disks on the middle level between the upper and lower folding plates and connected to a device for displacing both rows of insertion disks in such a way that an angle formed by common tangents of both rows of insertion disks is sufficiently large that the insertion disks essentially firmly supply interior folding edges of the gussets, said carriers including L-shaped angle pieces and strips mounted thereto parallel to the folding plates, a vertical leg of said L-shaped angle pieces being provided with a horizontal pin displaceably guided into a bore in said capping piece, an angle lever being mounted on said pin with a leg of said angle lever carrying rollers which are guided in a first side on a horizontal crosswise guide fixed to said frame and on a second side in a vertical guide of said capping pieces.  
     
     
       3. A device for forming a tube provided with gussets out of a single-layer or multi-layer, continuously pre-stressed material web comprising: 
       divided upper and lower folding plates mounted in a machine frame that determine a width of the tube when it is laid flat and over whose entrance sides the web is deflected in order to raise overlapping edge regions to be pressed in, said plates being adjustable in their distance from one another corresponding to the width of the tube to be formed and approaching one another in a direction of an exit region, at a right angle to a tube-forming plane and approximately in the shape of a wedge with an adjustable wedge angle;  
       two rows of insertion disks, each mounted on a generally horizontal arm of an L-shaped carrier and engaging in a middle level between the upper and lower folding plates for forming gussets, a distance between said rows being adjustable in the tube-forming plane, said carrier being pivotal around a crosswise axis and having, in said exit region, a generally vertical leg with an upper section and a lower section, said lower section secured on a capping piece mounted to said frame, said upper section rotatable relative to said lower section around a vertical axis pivot.  
     
     
       4. The device as set forth in  claim 3 , wherein said carrier in an entrance region is pivotally mounted on said capping piece and movable relative thereto in the plane of the insertion disks by a lever mechanism. 
     
     
       5. The device as set forth in  claim 3 , wherein in an entrance region of said device said vertical leg of said carrier is provided with a horizontal pin displaceably guided into a bore in said capping piece. 
     
     
       6. The device as set forth in  claim 5 , further comprising an angle lever mounted on said pin, a leg of said angle lever carrying rollers which are guided in a first side on a horizontal crosswise guide fixed to said frame and on a second side in a vertical guide of said capping piece.